Target shooting is a different story, but those guys, if serious, are doing things we would never do, e.g. tailor the load (powder type, primer type, bullet type to the specific rifle).
Some calibers are inherently more accurate than others, e.g. .375, but the build quality of the rifle and rate of twist of the barrel are more important than the caliber.
You left out sorting bullets by weight and controlling runout on the cartridge! I did all that for my .308 hunting loads. Why? Because I can.